The present invention relates to a slidable type constant velocity universal joint which is used chiefly in a front-engine front-drive type motorcar in such a manner that the same is interposed between an output shaft of a transmission connected to an engine and a wheel shaft connected to a front wheel disposed on the side thereof.
The prior art has known of such a type of universal joint of this kind that an outer member has an inner diameter cylindrical surface provided there in with an inner member having an outer diameter spherical surface and a cage member mounted on the inner member and having an inner diameter spherical surface and an outer diameter spherical surface which are eccentric to each other; a cage member is provided with plural balls mounted in respective windows, and the respective balls are in engagement with corresponding respective pairs of longitudinal directional guide grooves made in mutually facing surfaces of the outer members and the inner member. It is usual with this type to be so arranged, that the cage member is in direct contact, at its outer diameter spherical surface, with the inner diameter cylindrical surface of the outer member. This arrangement gives rise to inconveniences, i.e. that because the contact between the cage members and outer member becomes a linear contact, the two members are subjected to large pressure contact forces against each other, and consequently the two are liable to be damaged mutually and are made difficult to make mutual smooth slide movement. Furthermore, such an occasion is taken into consideration that the outer member and the inner member are mutually bent.
This arrangement also gives rise to an inconvenience that each ball tends to be pushed and accordingly the cage member is given a moment about the joint center. Consequently, there is generated especially large pressure contact forces at upper and lower contact points at which the cage member and the outer member are in contact one with another and thereby striking marks are liable to be formed at the contact points.